Superjunction device having a dielectric termination and methods for manufacturing the device
View Patent ↗A superjunction semiconductor device is provided having at least one column of a first conductivity type and at least one column of a second conductivity type extending from a first main surface of a semiconductor substrate toward a second main surface of the semiconductor substrate opposed to the first main surface. The at least one column of the second conductivity type has a first sidewall surface proximate the at least one column of the first conductivity type and a second sidewall surface opposed to the first sidewall surface. A termination structure is proximate the second sidewall surface of the at least one column of the second conductivity type. The termination structure includes a layer of dielectric of an effective thickness and consumes about 0% of the surface area of the first main surface. Methods for manufacturing superjunction semiconductor devices and for preventing surface breakdown are also provided.
1. A superjunction semiconductor device comprising:
(a) at least one column of a first conductivity type extending from a first main surface of a semiconductor substrate toward a second main surface of the semiconductor substrate opposed to the first main surface;
(b) at least one column of a second conductivity type extending from the first main surface toward the second main surface, the at least one column of the second conductivity type having a first sidewall surface proximate the at least one column of the first conductivity type and a second sidewall surface opposed to the first sidewall surface; and
(c) a termination structure proximate the second sidewall surface of the at least one column of the second conductivity type, the termination structure comprising a layer of dielectric of an effective thickness and consuming about 0% of a surface area of the first main surface of the semiconductor substrate, a first surface of the termination structure being proximate to the at least one column of the second conductivity type and an opposing second surface of the termination structure being in direct contact with a material that encapsulates the semiconductor substrate.
2. The superjunction semiconductor device of claim 1 , wherein the termination structure comprises one of a trench filled with dielectric and a passivation layer.
3. The superjunction semiconductor device of claim 1 , wherein the dielectric is one of air, a nitride, an oxide, a semi-insulating polycrystalline silicon (SIPOS), a silicon-rich nitride, silicon carbide, and a combination thereof.
4. The superjunction semiconductor device of claim 1 , wherein the termination structure comprises one of glass, ceramic, plastic, and a combination thereof.
5. The superjunction semiconductor device of claim 1 , wherein the termination structure comprises an inner layer/underfilling of a package that encapsulates the superjunction semiconductor substrate.
6. The superjunction semiconductor device of claim 1 , wherein the effective thickness is at least about 150 μm.
7. The superjunction semiconductor device of claim 1 , wherein the dielectric has a dielectric constant of about 1.0 to about 4.5.
8. The superjunction semiconductor device of claim 1 being one of a superjunction metal-oxide-semiconductor field-effect transistor (MOSFET), a superjunction metal-semiconductor field-effect transistor (MOSFET), a superjunction Schottky transistor, a superjunction Schottky diode, a superjunction insulated-gate bipolar transistor (IGBT), a thyristor, and a superjunction diode.